Steam heating system



Dec. 28, 1937. J, VAN V LPEN 2,103,835

STEAM HEATING SYSTEM Original Filed Jan. 17,- 1936 2 ts-Sheet 1 Inlfeni'f (/0722 %2%612 0 M WV MK J rag? Dec. 28, 1937. J, VAN VULPEN 2,103,835

- STEAM HEATING SYSTEM Original Filed Jan. 17, 1936 2 Sheets-Sheet 2 I ITLJ Q1117)!" (fail? %12 %Z 822 PM US Cli Patented Dec. 28, 1937 UNITED STATES STEAM HEATING SYSTEM John Van Vulpen, Chicago, 111., assignor to Vapor Oar Heating Company, Inc., Chicago, 111., a corporation of New York Original application January 17,- 1936, Serial No. 59,568. Divided and this application August 13, 1936, Serial No. 95,758

10 Claims. (01. 237-2) This invention relates to certain new and useful improvements in a heating system particularly adapted for use on aeroplanes, or in other situations where there is available a constant supply of otherwise wasted heat. The present invention is a division of my copending application Serial No. 59,568, filed January 17, 1936.

In aeroplanes, or other devices involving an internal combustion engine, there is (when the engine is operating) a continuous flow through the exhaust pipe of highly heated gases which are vented into the atmopshere, substantially all of this heat being wasted. In a heating system of the type herein disclosed, a portion of this other- 15 wise wasted heat is utilized to constantly supply heating medium to a radiator positioned in one of a pair of similar conduits, each having an inlet opening communicating with the outer air.

Each conduit has a pair of alternative outlet 20 openings, one of which discharges back into the outer air, and the other of which leads into a main conduit from which the air stream is discharged into the space to be heated. Means is provided for maintaining a continuous flow of air through both conduits, and thermostatically controlled valve means is provided for determining the relative proportions of heated and unheated air that are selectively passed through the alternative discharge outlets into the main conduit and thence intov the compartment to be heated. It will be understood that there is a continuous flow of highly heated air through one of the conduits, but only a selected portion of this heated air is mixed with a selected portion of the unheated air from the other conduit and the mixture is then delivered into the compartment. mainder of each air stream is'discharged back into the outer air.

Any suitable form of means may be provided for continuously heating the, radiators, a preferred means being disclosed and claimed in the parent application Serial No. 59,568 hereinabove referred to and from which the present application has been divided. v

The general object of this invention is to provide an improved heating system of the type briefly described hereinabove and disclosed more in detail in the specifications which follow.

Another object is to provide a simple and eifective heating apparatus utilizing heat derived from the waste gases of an internal combustion engine.

Another object is to provide an improved heating system utilizing a radiator continuously maintained at a maximum temperature, together with thermostatically controlled means for changing the proportions of heated and unheated air delivered into the compartment to be heated.

Other objects and advantages of this invention will be more apparent from the following detailed description of one approved form of apparatus constructed and operating according to the principles of this invention.

In the accompanying drawings:

Fig. 1 is a perspective, partially diagrammatic view of the principal elements of the heating system.

Fig. 2 is a perspective view, similar to the upper left-hand portion of Fig. 1 showing a blower for forcing the air into and through the conduits.

Fig. 3 is a transverse vertical section through the generator and supply tank.

Fig. 4 is a wiring diagram of one suitable type of electrical control system for regulatingtthe temperature maintained by this improved heating apparatus.

Fig. 5 is a detail section of a modification in which the controlling-thermostats are positioned in the compartment to be'heated..

Referring first to Fig. 1, air forced into a pair of inlet air conduits l and 2 discharges into a main conduit 3 which delivers the air into a compartment to be heated, for example the cabin of the aeroplane. In the case of an aeroplane, outside air will be continually forced into the inlet conduits l and 2 by a suitable scoop device and the rotating propeller. If not used on a moving vehicle such as an aeroplane, a blower such as indicated at 4 (Fi 2) and driven by the motor 5 may be used for forcing a stream of air through the conduits.

The conduits Iv and 2 may receive only unheated outside air, or a portion of this air may be received from within the compartment. In any case, what may be described as unheated air is drawn or forced into each of the inlet conduits l and 2. s

A radiator 6 is positioned in one of the inlet conduits, for example the conduit, I, so that the air forced through this conduit, will pass in intimate relation to the radiator and be heated thereby. radiator 6 is constantly heated (as will be hereinafter described) to a rather high temperature, regardless of whether heat is needed within the compartment or not. i

The hot-air conduit I has a discharge outlet I at its end leading into the main conduit 3, and 60 also an auxiliary. outlet 8 in one side through which the heated air may be vented or dissipated into the outer air. Similarly, the cold air conduit 2 has a discharge outlet 9 leading into the main conduit 3 and an auxiliary discharge outlet in leading to the open air. A swinging vane or valve ll, pivotally mounted at one end on the shaft I2, is positioned in inlet conduit I so as to alternatively open or close the outlets and 8, or to direct desired proportions of the heated air through these respective outlets. A similar valve or vane I3 is pivoted at one end on shaft l4 and mounted in the inlet conduit 2 so, as to alterna tively open or close the two outlets 9 and In. The shaft" I2 is driven by a reversible motor I5, and the shafts i2 and I4 are connected by a pair .of intermeshing gears I6 and [1, so that the shafts will be driven in opposite directions and consequently the valves i l and I3 will be swung in opposite directions as the motor is rotated. In the position shown in Fig. 1, the valve II is so adjusted as to close the outlet 1 and open the outlet 8, all of the heated air being vented to the atmosphere. On the other hand the vane i2 is swung so as to close the outlet I0 and open the outlet 9 so that all of the air drawn in through inlet conduit 2 is discharged into the main conduit 3. In this position no heat will be added to the air delivered through conduit 3. valves II and I2 were swung to their opposite limits (so as to close the outlet 8 and open the outlet Hi), all of the air delivered into main conduit 3 would be heated. It will now be apparent that by adjusting the vanes II and I2 to some selected intermediate position, the proportions of the heated and unheated air that are delivered into main conduit 3 may be selected as desired so as to maintain any desired temperature within the compartment that is to be heated.

As far as the invention herein claimed is concerned, the radiator 6 can be continuously heated in any suitable manner, but preferably the radiator is part of the improved steam heating system claimed in the parent application, Serial N 0. 59,568, hereinabove referred to. This system comprises, in addition to the radiator 6, the improved boiler or generator l8 and the water tank or reservoir IS, the generator, radiator and tank being connected in a closed circuit or loop. This circuit is closed in the sense that no fluids are normally vented from this circulating system, but is open in the sense that a continuous circulation of these fiuids is normally permitted there being no valves or other controlling means normally used.

At 20 'is shown a section of the exhaust pipe through which the products of combustion are vented from the internalcombustion engine. This pipe 20 becomes very highly heated when the engine is in operation, but all of this heat is normally wasted. The generator I8 (see also Fig. 3) is so constructed as to fit closely about a section of the exhaust pipe 20 and utilize heat from the exhaust gases for generating steam. This generator is preferably of the saddle type so as to be easily positioned on or removed from the pipe 20 and comprises an inner U-shaped shell 2| adapted to rest upon the exhaust pipe 20, and a similar outer shell 22 spaced from the inner shell so as to form a U-shaped compartment comprising an upper steam space 23 and a pair of downwardly extending side legs 24 and 25 which are normally filled with water. It will be understood that the inner and outer shells 2| and 22 are connected by end 'walls 22 and the legs 24 and 25' are closed at the bottom so as to completely enclose the generating chamber. tween-the lower portions of the legs 24 and 25 is preferably filled with insulation 26 supported by the removable bottom wall 21 held in place by If the -tially atmospheric pressure.

The space bestraps 48 or other suitable securing means A pair of water inlet pipes 28 and 29 lead into the bottom portions of legs 24 and 25 so as to supply water thereto and keep this water up to a predetermined level such as indicated at a, this level being determined by the corresponding water level in the supply tank l9 as will be hereinafter described. It will be noted that only the upper portions of the bodies of water in the respective legs 24 and 25 are in intimate contact with the highly heated exhaust pipe 20, and the heat at this location is so intense that these relatively small bodies of water will be very quickly flashed into steam. The relatively cold water that enters the lower portions of the legs through inlet pipes 28 and 29 is at first spaced from the heating pipe 20 by insulation 26, but gradually approaches the pipe as the water rises in the legs thus preheating the water before it comes in contact with the hot exhaust pipe and is flashed into steam. By holding the water level at the desired height, the quantity of water in contact with the exhaust pipe and the rate of evaporation may be controlled to fit the requirements, and undesired super-heating of the steam will be prevented. It will be understood that this generator is of relatively small capacity. For example, if the exhaust pipe is about five inches in diameter the legs 24 and 25 may have an inner diameter of no more than one inch. The length of the generator will be just sufiicient to produce the desired quantity of steam, for example about two feet. It will be understood that the figures here given are merely by way of example, and are only intended'to bring out the fact that a relatively smallqquantity of water is held in the boiler or generator, and an even smaller quantity of water is in directsteam producing engagement with the exhaust pipe at any one time.

A perforated dry-plate 30 is preferably positioned horizontally of the upper portion of steam chamber 23, the purpose of this plate being to permit the upward passage of steam but prevent any appreciable quantities of water from rising above this plate in case bubbling or violent boiling takes place within the generator. The steam passes from steam chamber 23 through outlet 3| and supply pipe 32 into the radiator 6.

After the steam has been condensed in radiator 6 and has given up a portion of its heat to the air current flowing through conduit l, the resulting condensate drains down through pipe 33 into the supply tank I9. This tank is provided with an upwardly extending vent pipe 34 which is open to the atmosphere so that the entire steam heating system will normally oe under substan- Since some steam may find its way from the radiator through pipe 33 into tank IS, a condenser 35 is connected in the vent pipe 34 and the steam condensed'therein will drain back through pipe 34 into the tank I9. This prevents the loss of any substantial quantity of water from the system. It will be understood that the condenser should be so p0 sitioned as to be exposed to a cooling air stream. It might be positioned in conduit l in advance of the radiator 6.

Since the entire system is under substantially atmospheric pressure, the water will be at substantially the sanie constant levela in both the reservoir l9 and generator: l8. The required quantity of water may be supplied through the filling pipe 36 leading into the upper portion of tank i9 and provided at its upper end with funnel 31 and normally closed valve 38. By opening the normally closed valve 39 in a drain pipe 40 leading from one end of tank IS, the water in the tank may be drained out down to a predetermined level, thus determining the normal water level in the tank and boiler. Any other suitable means may be provided for filling the tank and generator to the desired level, which level may be varied in accordance with the rate of evaporation required. The connected pipe sections 4|, 42, 43, 44 and 45 lead from the bottom of tank l9 to the two inlet pipes 28 and 29 extending into the legs 24 and 25 of the generator. This pipe loop is normally open so that the water level in'the tank and generator will always remain substantially the same. A drain pipe 46 provided with normally closed valve 41-permits water to be drained from the heating system.

It should be understood that the parts of this the mercury column when the predetermined temsystem are all relatively fsmall, and the system requires only a very small amount of water. For example, a total quantity of one gallon of water in the system is suflicient for a heat delivery of 100,000 B. t. u. per hour.

It will be understood that when the engine is in-operation and heated gases are passing through the exhaust pipe 29, there will be a continuous flow of fluid through the 'closed loop oi the heating system. Water will be continuously vaporized in the generator l8, the steam flowing into radiator 6 and there condensing so that the resulting water flows back into tank |9. Water from tank l9 will continuously flow into the lower portion of generator l9 so as to maintain the water level constant in the tank and generator. When properly designed and adjusted, the rate of productionof steam in the generator It will be Just about sufilcient to supply the amount of steam that will be condensed in radiator 6 so that only condensate flows back through pipe 33 into the tank I9. If an excess of steam is produced, this steam will attempt to escape from tank l9 through the vent pipe 34 but will be condensed in condenser 35 and drained back into the tank l9 provided the excess is not too great.

In the event too much liquid is present in the system, a portion will escape as steam through the vent 34, thus automatically adjusting the amount of liquid required.

It will be noted that this steam heating system is very simple, there being no controls whatever other than those provided for maintaining the desired water level. This water level need only be tested and adjusted at long intervals, since substantially all of the water is retained in the system.

Since the radiator 6 will be continuously heated to a maximum capacity it is essential that only a desired proportion of the air heated by this radiator be directed into the compartment to be heated. For this reason the present invention including the system of air-proportioning valves hereinabove referred to has been provided, and, preferably, thermostatic means are used for adjusting these valves in accordance with temperature changes within the compartment. As shown in Fig. 1, a series of thermostats 49, and 5| are positioned in the main co'n'drdtj, beyond the mixing valves, so as-to respond to the temperature of the air being delivered into the compartment. Alternatively, these thermostats could be positioned in the compartment 3' itself as shown in Fig. 5. In any case these thermostats control the operation of the reversible motor l5 to adjust the valves II and i3 to the desired positions. In Fig. 4 is shown, by way of example, an electrical control system that could be used. It will be understood that any suitable control system may be adopted whereby the vanes can be adjusted in accordance with temperature conditions in the space to be heated. Referring now to Fig.

4, the power mains 52 and 53 are connected with v the respective terminals of the battery or other source of power indicated at 54. Each of the three thermostats 49, 59 and 5| (which may be designated as the low, medium and high temperature thermostats respectively) is adapted to complete a circuit therethrough when a certain predetermined temperature is reached in the space where the thermostat is positioned. These thermostats are shown as being of the mercury column type, each provided with a contact in constant engagement with the mercury column and another upper contact which will be engaged by perature is reached. For example the thermostats here shown may be adapted to close their respective circuits at 70, 13 and 76 Fahrenheit respectively. At 55 is shown a temperature selecting switch which may be moved to either of two positions to determine whether the temperature shall be maintained within a low or a high temperature range. When the switch is in the position now shown in solid lines, the temperature will be maintained in the low range, that is between 70 and 13. When this switch is moved to the dotted line position the temperature will be maintained in the higher range, that is between 73". and 76.

At 5615 shown a relay'magn'et adapted when energized to draw up the armature or movable contact 51 into engagement with a fixed contact 56. When magnet 56 is deenergized the contact 51 will fall into engagement with a second fixed contact 59. A second similar magnet 60 is adapted when energized to pull the movable con-. tact 6| up into engagement with a fixed contact 62. When the magnet is deenergized, movable contact 6| will fall into engagement with a second fixed contact 63.

When the certain predetermined temperature for which medium..thermostat 50 is adjusted is reached, an energizing circuit for magnet 56 will be completed as follows: From power main 52 through wire 64, thermostat 50, wire 65, magnet 56, wire 66, resistance 61, and wire 68 to the other main 53. When the temperature falls below the selected medium" temperature, this circuit will be broken and magnet 56 will be deenergized. When switch 55 is in the position shown in solid lines and the low temperature thermostat. 49 is in control, a circuit energizing the magnet 60 will be completed when the temperature for which thermostat 49 is adjusted is reached, this-circuit being as follows: From main 52 through wire 69, thermostat 49, wire 10, switch 55, wires 1| and 12, magnet 60, wire 13, resistance 14 and wire 15 to the main 53. v dotted line position the low temperature thermostat 49 will not be eilective, and this last described circuit will not be completed until the higher temperature for which thermostat 5| is adjusted is reached. In this case the energizing circuit will be as follows: From main 52 through wire 69, wire 16, thermostat 5|, wire 12, magnet 60, wire 13, resistance 14,' and wire 15 to main 53.

With the parts in the positions shown in the drawings, it will be noted that both relays 56 and 60 are energized since the temperature has reached the higher limit of the low temperature range, that is both thermostats 49 and 50 have be wasted in any event.

completed their circuits. It is now desirable that the supply of heat be shut off or diminished. A circuit is now completed as follows: From main 52 through wires 11 and I8, fixed contact 58, movable contact 51, wire 19, reversible motor l5, wire 80, movable contact 6|, fixed contact 62, wires 8| and 82, field 83 of motor l5, and wire 84 to the other main 53. The current flowing through motor IS in this direction will cause the motor to rotate in such a direction as to move the valves II and I3 toward the positions shown in Fig. 1, that is so as to cut off the heat supply. It will be understood that the motor is so geared as to move these vanes very slowly. Since the heat supply is being diminished, the temperature will drop and eventually the circuit through medium temperature thermostat 50 will be broken thereby deenergizing magnet 56 and permitting contact 51 to fall into engagement with fixed contact 59. This will break the circuit last described and motor l5 will stop. If the temperature continues to fall, the circuit through low temperature thermostat 49 will eventually be broken and magnet 60 will be deenergized so that contact 5| will fall into engagement with fixed contact 63. A circuit through motor I5 flowing in the opposite direction will now be completed as follows: From main 52 through Wire TI, fixed contact 63, movable contact 6|, wire 80, motor l5, wire 19, movable contact 51, fixed contact 59, wire 82, field 83, and wire 84 to the other main 53. This will cause motor E5 to rotate in a reverse direction so as to move the vanes in such a direction as to open conduit l and close conduit 2 and thereby increase the proportion of heated airv admitted to the compartment. As a result the temperature will be raised. Since the motor moves the vanes or dampers very slowly, after a few cycles the parts will tend to become stabilized so as to maintain the desired temperature without further adjustment. If it is desired to maintain the temperature in the higher range, the switch 55 will be moved to the dotted line position and the two thermostats 58 and 5| will cooperate to control motor IS in a manner that should now be pparent.

The blower motor 5 (if used) can be connected between the mains 52 and 53 through the wires 85 and 86. At 81 is indicated the shunt field of this motor. By means of switch 88 in the mains 52 and 53 the motor can be started or stopped, and it will be noted that the switch 88 is so positioned that when the blower motor is stopped the entire electrical control system will be inoperative. It will be understood that his motor 5 and its connections will be omitted'ln installations where a blower is not required, as in aeroplanes.

This heating system is not particularly eflicient as far as the conservation of heat energy is concerned, but this is not important since it is intended for use in connection with internal combustion engines or in other installations where the heat used for generating the steam will The radiator 8 is continuously heated, and is continuously heating the air stream in conduit I, (that is when the engine is in operation), and only a small portion of this heated air may actually be used. However, the same amount of heat would have been dissipated through the exhaust pipe so that this heat loss is unimportant. This being the case, the steam heating system may be permitted to operate continuously without any controls and therefore is very simple and effective in its operation. The parts are light and only a small quantity of water is used which makes the system particularly suitable for. use on aeroplanes where excess weight must be avoided. At the same time the desired temperature may be maintained in the compartment by simply proportioning the amounts of heated and unheated air that'are actually admitted to the compartment or other space the temperature of which is to be controlled.

I claim:

1. In a system for heating a compartment, a main conduit for delivering air intothe compartment, a pair of inlet conduits for delivering air into the main conduit, each inlet conduit having an inlet opening through which outside air flows in and having a pair of alternative discharge outlets one leading into the main conduit and the other to the outside air, means for maintaining a continuous air flow through each of these inlet conduits, a radiator positioned in one of the inlet conduits between the inlet and outlet openings thereof, means continuously supplying heating medium to the radiator, valve means in each inlet conduit for alternatively opening or closing the respective outlets, and means for simultaneously adjusting the valves .to determine the proportions of heated and unheated air delivered into the main conduit.

2. In a system for heating a compartment, a main conduit for delivering air into the compartment, a pair of inlet conduits for delivering air into the main conduit, each inlet conduit having an inlet opening through which outside air flows in and having a pair of alternative discharge outlets one leading into the main conduit and the other to the outside air, means for maintaining a continuous air flow through each of these inlet conduits, a radiator positioned in one of the inlet conduits between the inlet and outlet openings thereof, means continuously supplying heating medium to the radiator, a valve in each inlet conduit for opening or closing one of the outlets and simultaneously closing or opening the other outlet, and means for simultaneously adjusting the valves in opposite directions to determine the proportions of heated and unheated air delivered into the main conduit.

3. In a system for heating a compartment, a main conduit for delivering air into the compartment, a pair of inlet conduits for delivering air into the main conduit, each inlet conduit having an inlet opening through which outside air flows in and having a pair of alternative discharge outlets one leading into the main conduit and the other to the outside air, means for maintaining a continuous air flow through each of these inlet conduits, a radiator positioned in one of the inlet conduits between the inlet and outlet openings thereof, means continuously supplying heating medium to the radiator, valve means in each inlet conduit for alternatively opening or closing the respective outlets, means for simultaneously adjusting the valves to determine the proportions of heated and unheated air delivered into the main conduit, a reversible motor for operating said adjusting means, and thermostatic means responsive to temperature changes in the main conduit for determining the direction and amount of rotation of the motor.

4. In a system for heating a compartment, a main conduit for delivering air into the compartment, a pair oi inlet conduits for delivering air into the main conduit, each inlet conduit having an inlet opening through which outside air 1 7 let openings thereof, means continuously supplypartment, a

ing heating medium to the radiator, a valve in each inlet conduit for opening or closing one of the outlets and simultaneously closing or open- ,ing the other outlet, means for simultaneously adjusting the valves in opposite directions to de- ,termine the proportions of heated and unheated air delivered into the main conduit, a reversible motor for operating said adjusting means, and thermostatic means responsive to temperature changes in the main conduit for determining the amount and direction of rotation of the motor.

5. In a system for heating a compartment, a main conduit for delivering air into the compair of inlet conduits for delivering air into the main conduit, each inlet conduit having an inlet opening through which outside air flows in and having a pair of alternative discharge outlets one leading into the main conduit and the other to the outside air, means for maintaining a continuous air flow through each of these inlet conduits, a radiator positioned in one of the inlet conduits between the inlet and outlet openings thereof, means continuously supplying heating medium to the radiator, a valve in each inlet conduit for opening or closing one of the outlets and simultaneously closing or open- ,ing theother outlet, and thermostatically controlled means responsive to temperature changes in the main conduit for simultaneously adjusting the valves in opposite directions to determine the proportions of heated and unheated air delivered into the main conduit.

6. Ima system for heating a compartment, 2. main conduit for delivering air into the compartment, a pair of inlet conduits for delivering air into the main conduit, each inlet conduit having an inlet opening through which outside air flows in and having a pair of alternative discharge outlets one leading into the main conduit and the other to the outside air, means for maintaining a continuous air flow through each of these inlet conduits, a radiator positioned in one of the,

inlet conduits between the inlet and outlet openings thereof, means continuously supplying heating medium to the radiator, valve means in each inlet conduit for alternatively opening or closing the respective outlets, and thermostatically controlled means responsive to temperature changes in the main conduit for adjusting the valve means to determine the proportions of heated and unheated air delivered into the main conduit.

7. In a system for heating a compartment, a pair of conduits for supplying air to the compartment, each conduit having an inlet opening through which outside air flows in and a pair of alternative discharge outlets one of which supplies air to the compartment and the other discharging into the outer air, means for maintain-- thereof, means continuously supplying heating a medium to the radiator, valve means in each conduit for alternatively opening and closing the respective outlets, and means for simultaneously adjusting the several valves to determine the proportions of heated and unheated air delivered into the compartment.

8. In a system for heating a compartment, a pair of conduits for supplying air to the compartment, each conduit having an inlet opening through which outside air flows in and a pair of alternative discharge outlets one of which supplies air to the compartment and the other discharging into the outer air, means for maintaining a continuous air flow through each of the conduits, a radiator positioned in one of the conduits between the inlet and outlet openings thereof, means continuously supplying heating medium to the radiator, a valve in each conduit for opening or closing one of the outlets and simultaneously closing or opening the other outlet, and means for simultaneously adjusting the valves in opposite directions to determine the proportions of heated and unheated air delivered into the compartment.

9. In a system for heating a compartment, a pair of conduits for supplying air to the compartment, each conduit having an inlet opening through which outside air flows in and a pair of alternative discharge outlets one of which supplies air to the compartment and the other discharging into the outer air, means for maintain ing a continuous air flow through each of the conduits, a radiator positioned in one of the conduits between the inlet and the outlet openings thereof, means continuously supplying heating medium to the radiator, a valve in each conduit for opening or closing one of the outlets and simultaneously closing or opening the other outlet, means for simultaneously adjusting the valves in opposite directions to determine the proportions of heated and unheated air delivered into the compartment, a reversible motor for operating the adjusting ,means, and thermostatic means responsive to temperature changes in the compartment for determining the direction and amount of rotation of the motor.

10. In a system for heating a compartment, a pair of conduits for supplying air to the compartment, each conduit having 'an inlet opening through which outside air flows in and a pair of alternative discharge outlets one of which supplies air-to the compartment and the other discharging into the outer air, means for maintain- "sponsive to temperature changes in the compartment for simultaneously adjusting the valves in opposite directions to determine the proportions of heated and unheated air delivered into the compartment.

JOHN VAN VULPEN. 

